code: def __call__(self, approx, loss, i):
      raise NotImplementedError
  
file_path: pymc/pymc/variational/callbacks.py
imports: import collections
  from typing import Callable, Dict
  import numpy
label_desc: Use image node_id 1 for calling the Callback obj's underlying member method code with example usage: obj.__call__(approx, loss, i) without return types